Retirement-Related Benefit Plans' Impact on Income Before Income Taxes (Detail) - USD ($) $ in Thousands	3 Months Ended
	Aug. 31, 2019	Aug. 31, 2018
Pension Benefits | U.S. Plans
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	$ 9,856	$ 9,382
Interest cost	5,104	5,497
Expected return on plan assets	(8,573)	(8,467)
Prior service cost (credit)	2	29
Net actuarial (gains) losses recognized	4,629	3,272
Net Periodic Benefit (Credit) Cost	11,018	9,713
Pension Benefits | Non-U.S. Plans
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	1,391	1,219
Interest cost	1,193	1,399
Expected return on plan assets	(1,834)	(2,051)
Prior service cost (credit)	(9)	(8)
Net actuarial (gains) losses recognized	523	319
Net Periodic Benefit (Credit) Cost	1,264	878
Postretirement Benefits | U.S. Plans
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Interest cost	37	48
Prior service cost (credit)	(55)	(55)
Net actuarial (gains) losses recognized	(16)	(6)
Net Periodic Benefit (Credit) Cost	(34)	(13)
Postretirement Benefits | Non-U.S. Plans
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	429	392
Interest cost	282	291
Net actuarial (gains) losses recognized	158	115
Net Periodic Benefit (Credit) Cost	$ 869	$ 798